The invention relates to a signal generating means, and more particularly to a means for detecting the position and sensing the frequency of rotation of a rotary body.
Heretofore, detecting devices have determined position and frequency by the sensing of an emission from a rotating shaft, such as detecting the magnetic field of a rotating magnet or electromagnet, or responding to a light source on a turning element by using a light detector. In each such devices, the source of emanations is secured to the object whose motion is being detected. In another form, proximity detectors which use magnets, light sources, and acoustic generators as part of a stationary assembly, react to nearby variations in a passive media which is to have its motion detected. In still another form, position and motion detectors are made to include a specialized form for the rotating element, and operate to modify as a function of position, the emanations from a stationary source.